Various fuzing systems have been used to initiate detonation either by measuring the slant range or the vertical distance to ground of a ballistic vehicle approaching a ground target. The most sophisticated of these fuzing systems utilize radar techniques, including active transmitters and associated receivers aboard the vehicle to determine the shortest range to the ground; that is, the vertical altitude. When a predetermined range is measured, the radar receiver outputs a fire pulse signal to detonate the explosive aboard the vehicle. It is well known in the art that a given preselected detonation altitude yields the most efficient operation of the explosive against some ground based targets.
These radar based fuze systems are relatively expensive, require a significant amount of power aboard for their operation and are relatively susceptable to jamming signals. This jamming may cause either premature or negation of firing thus reducing the expected efficacy of the explosive force.